Wire is typically formed by drawing a metal substrate through an aperture in a die or draw plate. Wire is often reduced to the desired diameter and properties by repeated drawing through progressively smaller dies. After a number of passes the wire may be annealed either to facilitate more drawing or, if the drawn wire already exhibits the desired diameter, to maximize the wire's ductility and electrical conductivity.
Wire is commonly used for making internal connections inside electrical or electronic devices. Based on ductility and electrical conductivity requirements, the metals suitable for such wire are mainly platinum, silver, iron, copper, aluminum and gold. Wire is typically formed from such metals and their alloys, the most common of which are brass and bronze. A wire used for such a purpose may be solid or multi-stranded, and is often covered with a dielectric or insulating material such as plastic, rubber-like polymer or varnish.